I'm a complete beginner with recording. I do have a good PC and 3 DAWs that I can use. My question is, what else do I need? I'm trying to keep it under $300. I'll be recording a full band, as well as pop style stuff. So where should I begin?
$300 for full band might be bit of a stretch, especially if you want to be multitracking drums.

I guess you could go with an older 8 track-at-once recorder like the Korg D888 (Roland, Tascam, Zoom, etc.) for about $200:

Then get some kind of recording mic package, on this budget not sure. Maybe I'll go with 2 dynamics and 2 condensers, that way you can first track your drums with 2 overhead condensers and 2 mics, one on kick and one on snare, guitars via the direct out of the amps for scratch takes, then record guitars and vocals with the same mics once the drum takes are out of the way. For $100 that it very hard to find, maybe this package:

Although I haven't tried these mics.

Then you can transfer to DAW for editing or maybe even get a small audio interface to do overdubs in the DAW if you don't want to do them on the multitracker.

If you want to go PC only you'll need a bigger input count on the interface, so realistically you need a 8 inputs interface but maybe can get around with 4 inputs, but the interface itself will be around $400 or so.

Maybe something like this bundle:

but will still need at least two more dynamic mics for kick and snare, provided that you have direct out on a guitar or want to record piecemeal.

If you don't need drums and don't want higher count you can get one of the smaller packages, like this:

and maybe add a Sm57 dynamic mic for guitars or record guitars direct if you don't like the sound of the NT1A which for the price is probably the best microphone in a bundle to buy.